How can I activate the Blog menu entry for individual posts?

Hi there,

That's not possible without a custom solution unfortunately - it's not something the theme can control.

WordPress's menu system does not add a current-menu-item to the Blog page when viewing a single post.

Thanks for your understanding.

it goes like this:

current_page_parent a {
colour: #1e73be;
background-color: #dddddd;
}
this then applies to all posts and blog is always active,

maybe you can help next time!
Greetings

Glad to hear!